


The Beta and His Omega's Alpha

by DeadlyKittenKay (PrettyBlueIz)



Series: SPN ABO Bingo Aug-Dec 2017 [7]
Category: Supernatural
Genre: Alpha Dean Winchester, Alpha/Beta/Omega Dynamics, Alternate Universe - College/University, Alternate Universe - Roommates/Housemates, Anal Sex, Beta Jimmy, Blow Jobs, Incest, M/M, M/M/M, Masturbation, Multi, Omega Castiel, Porn Watching, SPN A/B/O Bingo, Twincest
Language: English
Status: Completed
Published: 2017-11-22
Updated: 2017-11-22
Packaged: 2019-02-05 11:51:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,935
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12793965
Author URL: https://archiveofourown.org/users/PrettyBlueIz/pseuds/DeadlyKittenKay
Summary: The Novak twins have kept something important from Dean. Something that they both want to share with him, but don't know how. And to make things even more complicated, Castiel really wants to make Dean their Alpha in every way imaginable. The question is how?Dean loves having the twins for roommates, their awesome, fun and great on the eyes. And he might have a secret twin kink. Just how can he bring his fantasy to life?





	The Beta and His Omega's Alpha

**Author's Note:**

> This was written for the SPN ABO Bingo on Tumblr. This fills the Dean/Cas/Jimmy square
> 
> Thank you to hey_you_with_the_face for reading this over for me!

When it came to presenting, it was rare to have a set of identical twins not present the same way. It’s even more rare to have one of set male twins to have an omega presentation. But when Jimmy and Castiel Novak presented just shortly after their fifteenth birthday, their parents worried. Not so much for Jimmy the Beta, but for Castiel the rare male omega.

Castiel and Jimmy had a special bond many attributed to them having shared literally everything since conception, so no-one had bat an eye when Jimmy comforted an overly emotional Castiel, holding him tight within his arms, whispering, and nuzzling into his brother’s hair and neck. They didn’t even do a double take when Jimmy went on his first date and Castiel was left at home as fat jealous tears ran down his face. They all brushed it off to Castiel wanting to be out on a date too. They never imaged that he wanted to be on the date with Jimmy.

For Jimmy and Castiel, they were each other’s firsts. First kiss. First wet dream, first blow job… you name it, they did it to and with each other. The loved each other, and Jimmy vowed to protect Castiel until his dying breath.

That is until the moved into a shared dorm with Dean Winchester. Dean was all Alpha with Omega tendencies that confused the hell out of Jimmy, but much to his surprise -- and to be honest, his dick’s delight -- aroused Castiel like none other.

Their freshman year, they spent many nights in Castiel’s bunk, using the pretenses that Castiel had nightmare and Jimmy helped him through it. When in reality, the only thing Jimmy was helping Castiel with was climaxing. Many nights of dicks rubbing together as they swallowed each other’s moans, of mind blowing blow jobs. Not to mention Jimmy’s personal favorite, covering Castiel’s mouth while he jerked him, whispering all the filthy things he wanted to do to his brother and Dean, if Dean were so inclined.

And Dean was a sweetheart to the twins. He made sure that if he were up for classes first to have coffee for both -- a habit they took up too, as Castiel had learned that Dean was like an angry bear in the mornings. Something that both terrified and turned him on.

Or like Jimmy’s favorite SNL character would say, “Well, mark me as scared _and_ horny.”

He also asked what they needed from the store when he was going on what he called a milk run and stayed at his friend Benny’s while Castiel was in heat. Dean also often initiated movie nights, in an attempt to get to know them. Jimmy would try to get Castiel to open up to the Alpha, because if the Novaks ever had children, Castiel would need a virile Alpha like Dean. Plus Jimmy could clearly see the attraction between the two and as much as he loved Castiel, he would never be the one to deny him this.

That realization unfortunately caused a bit of a skirmish between the brothers. Jimmy’s eagerness sometimes led Castiel into fits of depression, thinking that he wasn’t giving his brother what he needed or pleasing him in the way he wanted. This also often led to Jimmy taking his brother hard and fast, making Castiel spill all over Dean’s sheets. Which they changed of course, saying that they spilled their drink or some other extravagant lie.

The brothers got better at keeping their secret. They saw Dean as a dear friend and would preen when they would catch him saying the same in kind to his family. Sure there were bumps in the road, as there always were with roommates -- let's just say Dean being raised by a military father meant he had certain habits and Jimmy could be a slob -- but they learned to adapt, improvise, and overcome.

But then Jimmy had the brilliant idea to show Dean what he and Castiel shared. He had suggesting letting a touch or look or even a nightly moan slip to where Dean would notice, but Castiel had been afraid. Scared that their secret was too taboo for even someone as open minded as Dean. But eventually he let the idea drop all together just for Castiel’s happiness.

Then one Friday while sharing pizza and watching Star Wars, the topic of porn came up.

Not that it was unusual of a conversation. In fact, Dean and Jimmy often compared notes about their favorite porn. But this time, Dean was more curious as to if the twins ever watched the porn together.

“I just mean because you guys are super close and as close as I am with my brother, I don’t think I could watch porn with him or in a room full of dudes,” Dean rushed to explain before chugging the rest of his cola.

Castiel blushed and picked an olive off his pizza while Jimmy laughed.

“You and Sam are what, four years apart,” Jimmy asked. Dean nodded before snagging the pepperoni sitting on Castiel’s plate earning a smile from him.

“Cas and me, we’re fourteen minutes apart, so I guess that helps,” Jimmy laughed.

“Woah… is that common?” Dean asked look between the two.

Castiel answered this time, shaking his head. “Both our parents are Betas but our mother comes from a long line of Omegas. We’re,” he points between himself and Jimmy, “are the first males on her side. Since our great-great-great-great-grandmother, they’ve had nothing but girls. All Omegas.”

“Cas, you’re rambling,” Jimmy teased, bumping his shoulder against his brother.

“My apologies,” Castiel muttered as Dean chuckled and said. “Shut up, Jimbo, it’s cute.”

Castiel smiled up at Dean before returning his attention to his pizza. This time offering the slice of pepperoni he had just picked off directly to Dean.

“So as you know, Beta and Beta pairings happen but are rare to form offspring, let alone multiples. Because our genetics have been altered with for so long, the female Beta body isn’t necessarily equipped to carry to full term. And when you add multiples into the equation,” Castiel trailed off.

“They label you high risk.” Jimmy finished.

Castiel nodded. “Our mother had to have an emergency cesarean. Dad likes to say that Jimmy was trying to rock climb up mom’s throat because he was breech and I was trying to be a mummy.”

Jimmy wraps his arm around his brother’s shoulder and kisses his temple. Jimmy can smell the faint sourness to Castiel’s typically sweet scent and he can’t help kissing his way to his brother’s ear lobe, where he flicks his tongue against it before gently biting it.

Castiel squirms and pushed his brother away, scowling at him in the process. “I’m sorry I brought the mood down, but yes, Dean,” Castiel slapped away Jimmy’s hand which suddenly kept trying to get under Castiel’s shirt. “We have watched porn together.”

“It’s part of the bond you to have together right,” Dean asked as he started to pick up the empty plates.

“In a manner of speaking,” Castiel responded. Dean didn’t notice that the twins were communicating to each other at that time because if he had been paying attention, he would have seen Castiel mouthing the word ‘no’ repeatedly as Jimmy mouthed ‘ask him’.

Jimmy kept his eyes on his brother as he said, “I think we should all watch porn. Tonight. Right now.”

Castiel groaned and put his face in his hands as Dean chuckled, coming back to sit on the bed where he was before. Castiel pretended that he did _not_ notice the way that Dean was sitting closer to him or the warmth of his body as the Alpha’s thigh pressed against his own.

“You a little eager there, aren’t you Jimmy,” Dean teased, reaching over Castiel to get a pillow from behind Jimmy.

Jimmy shifted so that he can see both Dean and his brother and shrugged. “What can I say, it’s been awhile since I’ve watched porn and even longer since I got off.”

Castiel was quick to open his mouth, wanting to point out that he’d come just this morning with Castiel’s lips wrapped around his dick, but snapped his jaw shut and glared at his brother instead.

Dean chuckled again. “Well, if Cas is okay with it then let’s do it. What’s the worst that can happen?”

Castiel pointed to himself and said softly, “Omega.”

Dean leaned close to Castiel. “Do you trust me, Cas,” he asked so softly that only Cas could hear him. Castiel nodded and looked at Dean, his blue eyes locking to Dean’s green. “I won’t hurt you. Or Jimmy,” he swore with a small smile and Castiel felt the air from his lungs leave him in a surprised whoosh. As if with that promise Dean was telling him so much more but he couldn’t decipher the code just yet.

Castiel let out a long heavy breath and nodded. “It’s just a video, we can do this.” He wasn’t sure if he was convincing himself or the others.

Jimmy patted Castiel’s thigh. “Dean’s already in sweats and we’re still in jeans. Get comfy Cas. Don’t want to hurt your dick do ya,” he teased with a wink before grabbing a pair of basketball shorts and lumbering off to the the shared bathroom connected to their room.

“You sure you’re okay with this, Cas,” Dean asked softly as Castiel reached for the fly of his jeans and popped the first button.

Castiel nodded. “Just uh…don’t hold back.” He wasn’t sure why he said the last part like a question. He honestly didn’t want Dean to restrain himself. Plus Castiel seriously wanted to get a peek at what Dean’s Alpha cock looked like. Maybe he’d even get the chance to see what he liked.

“Yeah…” Dean’s eyes were watching Castiel’s hands as he worked the rest of his fly open. “You either, Cas.”

Jimmy came back wearing just the shorts now and popped a video into player. He took his spot next to his brother, who had shifted to sit up straighter once he was stripped down to his shirt and boxers.

Jimmy wanted to make a joke about how handsy Castiel can be during porno but chose to keep quiet and see what happened.

At first nothing really happened. All three men were definitely sporting decent chubs to start with and as their viewing continued, Jimmy could see his brother and Dean swell in their pants. He shifted again, trying to fight the urge to touch Castiel like he normally would.

When Jimmy shifted, it had tugged his shorts down a bit and Castiel caught the flash of his creamy skin just below his hip. Without even thinking, his hand, which hand been clenched in a fist between him and his brother, moved to brush against the skin. Jimmy let out a soft sigh and Castiel couldn’t help but smile at his brother’s reaction.

That was until he chanced a glance at Dean. His eyes flicked to the impressive tent Dean had in his sweats before he looked up to his face. Dean’s green eyes were darker. The want and need clearly there as he stared back at Castiel.

“Cas…” Dean’s husky whine was what snapped Castiel’s restraint. He wrapped his arms around Dean’s neck and crushed his mouth to Dean’s.  A moan sounded at that moment that Castiel was pretty sure belonged to Jimmy’s as Dean’s hand grabbed Castiel’s hip trying to pull him closer too.

Castiel had often thought about what it would be like to kiss Dean. Maybe playful light bites to the lips. Or sweet, gentle movements, slowly opening him up. But now, now that he was experiencing the real deal, he knew he was wrong.

Dean’s kiss was powerful, strong. The way he sucked on Castiel’s bottom lip made him whine and roll his hips into Dean’s thigh. And when Dean opened his mouth up, it was full of heat and hunger. Their teeth knocked together at least twice. Castiel was pretty sure he bit Dean at one point but neither seemed to care.

When they finally broke apart, they were both panting for air. Castiel fell back to his spot in the middle, wincing at the feel the slick on the back of his thighs. Dean pulled his shirt off, tossing it to the floor as he looked over to Jimmy who was slowly pumping himself. His eyes locked on Castiel’s tented boxers.

“Take them off,” Jimmy instructed and smirked at Castiel’s whine as he complied with Jimmy’s wishes.

Jimmy’s eyes locked onto Dean’s. Dean rubbed himself through his sweats as he watched Castiel submit to his brother before his eyes settled on Jimmy’s cock. Thick and veiny. The mushroom head nearly purple, slick with the precome Jimmy smeared along it with his thumb.

“Come here,” Dean insisted pleasantly happy to see Jimmy lean over his brother. Jimmy licked at Dean’s lips, teasing him, forcing him to open to him before he tongue fucked his mouth. He swallowed Dean’s moan when Castiel’s hand laid on Dean’s stomach, his fingertips lightly grazing the flesh above the elastic waistband of his sweats.

Once Jimmy had enough of  tasting Dean, he sat back in his spot, his hand going back to his own dick as he watched the other two.

Castiel’s eyes were closed and his head leaned back against the wall as he stroked himself while his right hand slowly reached into Dean’s pants. Dean hooked his thumbs into his waistband and pulled the thick cotton pants off, giving Cas better access. He even went as far as wrapping both their hands around his dick, setting the pace and squeezing Cas’ hand to tighten his grip.

Castiel moaned when Dean leaned over to him and began to lick and suck on his neck. He whispered for Cas to move his hand faster in between each bruising kiss he left behind. Jimmy, not wanting to be left out, leaned forward and flicked his tongue against the slit of Castiel’s cock, tasting the salty taste of his precum. He moved his brother’s hand so that he could wrap his lips around the head.

Castiel gasped at the feel of Jimmy’s warm, wet mouth. The way he swirled his tongue and hummed around his dick sent electric shockwaves throughout his body. He began to jerk Dean in sync with Jimmy’s bobbing up and down on his own length; he was sucking him down deep and hard. When Castiel tried to thrust into his mouth, a strong hand pulls his legs wider, before massaging his thigh as it made its way to his balls. Instantly he knew it was Dean’s hand, the callouses from his welding job and working the car offered a whole different sensation than to the smooth touch of Jimmy’s that he was used to.

He wanted to feel Dean’s hands all over his body. He wanted to feel Jimmy’s too. He felt so greedy wanting them both but he couldn’t help the need that washed over him.

Dean could feel the muscles in Castiel’s thigh tighten against his arm as he cupped him. He gently massaged him, rubbing his thumb along Cas’ perineum. Dean moaned against Castiel’s neck when he gasped his name, his hips thrusting up and causing Jimmy to take more of Cas in and... _Holy fuck_ , that sight was so much better than what Dean had ever imagined.

Jimmy pulled himself off of Castiel’s cock with a pornographic slurping noise. He licked his lips as his eyes locked onto Dean’s hungry ones. Dean pulled away from where he was marking up Cas long enough to lick his way into Jimmy’s mouth. He moaned loudly, one hand holding Jimmy by the back of the head as the hand that was touching Cas moved to start stripping Jimmy’s dick. Jimmy broke the kiss, pressing his forehead to Dean’s as he fucked his fist, feeling his balls start to tighten. As much as he would love to cum all over Dean’s hand, he didn’t want Castiel to feel left out.

Not that this was a worry anymore because suddenly, it wasn't just Dean’s fist around him, alternating from a tight squeeze to a barely there tunnel, but now there was a tongue at the head, flicking against him every time he thrust up into Dean’s fist.

 _Flick. Flick Flick_.

And fuck it all if his brother didn’t know how to play him like a goddamn fiddle because his hand was there, teasing his hole with tiny little pushes of his fingers.

Dean’s hand was still on the back of Jimmy’s head, holding him, watching him.

“You like that Jimmy,” Dean asked, his voice gruff and fucking sinful as he clenched his fist tighter. Jimmy’s hips stuttered but he fucked his hips up faster, gasping with each upstroke. “You gonna cum for us Jimmy? Gonna paint us with your cum?”

 _Holy shit_ , Jimmy thought as the white light explodes from within him. “Nnnnnngh,” is what really came out of his mouth but in his mind he was shouting ‘Yes! Yes! God fucking yes!’.

He was amazingly over loaded.

Dean’s touch moved to the base of his cock, holding him as Castiel’s tongue cleaned up the ribbons that clung to him. He felt himself twitch as Dean gave one final tug and placed a kiss to Jimmy’s lips.

Jimmy hummed and nearly collapsed back into his spot, giving his brother a lazy smile. “Your turn,” he croaked, making Castiel chuckle. He watched as Cas crossed his hands to grab the hem of his shirt before pulling up and over his head.

“You should fuck Cas,” Jimmy said to Dean. Dean smirked and glanced at Castiel who nodded in complete agreement.

Dean looked back at Jimmy. “You don’t mind sharing?”

Jimmy could tell by the quick quirk of his eyebrow, Castiel caught that too and decided to save that for an after sex discussion. “Fair is fair man. You two do me, now you do you.”

Castiel laughed and crawled into his brother’s lap. “You’re so useless after you come,” he teased, giving his brother a filthy kiss. The twins could hear Dean whine behind them and they pulled apart to look at him.

“See something you like?” Jimmy drawled, his post coital haze making him sound nearly drunk.

“Two somethings,” Dean said.

Castiel looked back down at his brother, giving him a chaste kiss. “I love you,” he said softly, earning a smack on the ass from Jimmy.

Jimmy laughed when Cas squeaked and glared at him before moving over to Dean.

“How do you want to do this,” Dean asked, suddenly shy.

“I want Jimmy to watch,” Cas said simply as he straddled Dean’s lap.

Dean moaned when the strong scent of slick and Castiel hit him, the smell alone making his dick twitch in anticipation. Castiel placed his hands on Dean’s shoulders and looked down at the Alpha’s cock. He was much longer and thicker than Jimmy and Cas was a little worried as he’d never had an Alpha before. Castiel told Dean as much.

“I won’t hurt you,” Dean promised as he helped line himself up to Castiel’s slick covered hole.

As Cas slowly sank down on Dean; both men moaned at the sensation. For Dean the perfect heat and tightness gradually swallowing him whole was unlike any other feeling he could remember. For Cas, the feeling of being full and complete had his inner Omega chanting _safe, mate, mine_ on repeat.

Once Dean was fully sheathed inside Castiel, he placed his hands on the Omega’s waist and let him set the pace. He didn’t want to hurt him or to rush him. Castiel smiled at him, moving himself closer to kiss the Alpha below him. This movement made Castiel’s hips roll into Dean’s, taking him in deeper at a new angle and causing him to moan into Dean’s mouth.

Jimmy watched in rapt attention as his brother started to move faster. Little by little Castiel rocked his hips. Forwards and back. Up and down. Dean’s hands roamed all over Castiel’s body; They tangled in his hair as they kiss. One hand played with his nipples as the other works his cock in time with their movements. Jimmy regretted being the first to come because he was pretty sure watching his brother fuck his long time fantasy was the hottest thing he’d ever seen.

Dean’s dirty talk was second.

And Dean was not sparing Castiel from that either as he talked to him. Telling him how good it felt to be balls deep in him. Asking Cas if he likes the Alpha cock he was impaling himself on. The only responses he got out of Castiel at this point were broken moans and chants of Dean’s name as he fucked himself faster on Dean.

Castiel braced himself by placing his hands flat on the wall behind them as Dean’s hands grabbed at the flesh of his ass and helped him bounce. Both men were now panting, their skin flush from their exertion. Eyes locked on each other as they worked in tandem to bring the other one pleasure.

When Cas cried out, his back arching and thighs tightening around Dean, Dean knew he was there. Being able to watch Castiel as he fell over that cliff was enough that his knot swelled and locked itself inside of him.

This is the final feeling that made Cas gasp Dean’s name as he collapsed onto the Alpha’s shoulder. Dean held him close, fucking into him as he fell over the edge himself, spilling into the Omega. He slowed his movements eventually and came to stop, his arms still tight around Cas. Castiel laid there, spent against his chest; their come was starting to cool and feel tacky but that was nothing compared to feeling the beating of both their hearts.

Dean hissed when something cold touched his stomach. He opened his eyes to see Jimmy closer to them now, kissing Cas’ shoulder as he wiped between them. Cleaning them up.

“Good thinking,” Dean said sleepily, carefully repositioning himself and Cas to lay down.

“The perks of dating a Beta. We always think straight.”

Dean huffed a laugh and kissed the top of Castiel’s head; he swore the Omega purred at him.

He looked over at Jimmy who laughed. “Yes, Castiel purrs after sex. He’s super fucking clingy too.”

“I don’t mind,” Dean confessed.

“Awesome,” Jimmy smiled and kissed Dean’s forehead. “Let’s talk about how this is all gonna work in the morning, ok?”

Dean nodded and tried to hide his yawn. “In the morning,” he repeated before drifting off.

**Bonus**

They do talk about it and apparently the twins weren’t as sly as they thought they were. Dean had his suspicions about them from day one. But it wasn’t confirmed for him until he was woken up in the middle of the night by -- whom he thought was Cas -- moaning.  When he had peeked into the bed across from him and saw that Jimmy was not in his bunk, but his phone was still on the night stand and there was obviously someone in the top bunk with Cas, he did the math.

Dean had also confessed that since that night, he would purposely pretend to be asleep so he could jerk off to the the twins screwing around.

Castiel had laughed and called him a pervert.

Jimmy pretended to be scandalized.

Dean made it up to them by blowing them both before morning classes.


End file.
